Insulator pin



- Jan. 24, 1928.

A. o. AUSTIN INSULATOR PIN Original Filed May" 12. 1920 INVENT E' M A? M5 44 Patented Jan. 24, 1928.

UNITED, STATES PATE O E:

ARTHUR o. AUSTIN, or Bummer. OHIO, 'assreuoafsv Mam lassrenmnurs, To

THE OHIO BRASS compan or MANSFIELD, ion c, A eoaronarrou or NEW JEB-SEY.

Q'INSULATOR rm.

on application filed Kay 12, 1920, Serial 110380.826. Divided-andthisapplication filed September 4, 1925. Serial No.54,430.

This invention relates .to pins for supporting insulators for variouselectrical conductors; and has for its object'the provision of a devicewhich shall be of improved-construction and operation, and Whichshall beeconomical to manufacture and provide ef' licient distribution of thematerial -withoutinterfering with the electrical propertiesof theinsulator. a The invention is exemplifiedin the combina-tion andarrangementof parts shown in the accompanying drawing and described inthe following specification, and-it is more particularly pointed out inthe appended claims. I

In the drawing Fig. 1 is an elevation of a pin showing one embodiment ofthe present invention with the separately formed base in section;

Fig. 2 is a horizontal section on line 2--2 ofFig. 1.

This application is a division of appli'ca tion,Serial No. 380,826,filed May 12, 1920.

Insulators for electrical conductors are supported in a variety of Ways,one of the common means being by the use of pins carried by thesupporting structure and bearing the insulator fitted over theendthereoi Such pins are used for supporting insulator: on metal and woodenarms and pole tops and also on various constructions other than regularline Wire supports. A pin to meet the requirements to which it issubjected must have the necessarymechanical strength to Withstand thestressesbrought upon "it and should not materially lower the fiasliovervoltage of the insulator or otherwise diminish the electrical efficiencyof the insulator. The cost of manufacture should be kept as low aspossible and the pin should provide the required strength Withoutsetting up undue stress in the fragile material of the insulator whichit carries. The pin should also be adaptableto various conditions whicharise in line construction and other electrical installations Whereinsulators are used,.an'd it is also desirable that the pins should beso designed that a large variety can be made from as small a variety ofstock as pomible.

From the embodiment of the invention shownin thedrawing, it willbeapparent that the small body diameter of pins 0011- structedinaccordance with this invention permitsdeveloping the maximumflashover5 voltage value of the insulator since the small diameterofthe pin bodykeeps the outer surfaceotf the body" at. a maximum distance from thelower edge of the' insulator itself.

It Will also be seen that the supportingbase 00 and the body portionofthe insulator pin are made: in separate parts which permits the use ofa. base having sufficient area so that tliexcross-arm upon Which thebase rests will not :be crushed under bending moment. The 05construction permits of a. balanced arrange ment and at the sametimedoes not sacrifice the electricalproperties of the insulator. Inpins having a small base formed integrally with the pin, the bendingmoment upon 10 the pinforces the edge ioftheibase into con tact withtheupper face of the summit ing structure so that where the structure ismade of Wood, thefibresare crushed at the edge of: the base. permittingthe pin to lean I to onesideand loosening the connection with thesupport. It isiinpractical to form apin 'With an integral base ofsufficient area to overcome this difli'culty, tor the reason that I ifthe'pin is cut from apiece of stock of large diaineterithe Waste is toogreat to justify a sufficient expanse of base, and if it is undertakento upset or savage a smaller piece of stoclcto form the base, it isimpossible to expand the material a sull' cient amount to give abaseofthe required extent. Such operation also tends to form laps or flawsin the metal. Where the base is formed separately from the pinandisprovidedwith meansto hold the two rigidlytogethen when the pin isinstalled, the base maybe made of any'desired' extent and shape and pinsmay be standardized so that the same pinsmay be used with a largevariety of supporting bases. pin may be secured to the base by means ofa tapered end fittingin atapered socket and the taper may besoproportioned that thepins may be readily made With a sWaging-machinefrom straight-bar stock I without the loss of material. No finishingwhen a bending moment is applied, and at the same time the taper shouldpreferably be such that the pin will not bend in the smallsections, thesmaller portion of the pin being reinforced by the. base. When the baseand body are assembled they are held together so that they will work asa unitary struetureand the main body of the pin may be made in straightsection or given a taper,

which will give uniform strength for the bending moment, or it may bemade in stepped diameters, if desired.

The insulator may be secured to the pin in a large variety of ways,depending upon conditions. .In some cases a lead tip may be cast orpressed on'the pin which will form a cushion between the hard metal andthe porcelain. pin may, under some conditions, be provided with aroughened surface, or with resilient flanges or projections, to reducethe danger of cracking the insulator under expansion and contraction oftemperature changes. Another method of securing the insulator to the topof thepin is to provide the end of the pin with large or small threadswhich can be adapted to a thimble of sheet material threaded into theinsulator.

In thisconstruction the threaded parts may be. cone-shaped and theinsulator may be tightened downfirmly and afterwards the wire groove inthe insulator may be properly alined by turning the pin relative to itssupporting base. *The thimbles, however, instead of being cone-shapedmay be cylindrical so that they can be turned upon the pins to aline thewire grooves without loossuing the insulator on the pin. Where thisarrangement is made, the pin can be rigidly attached to the supportingbase. Under most conditions, however, the pin and base will be separablewhich will permit-combinations of various forms of pin with dif ferentkinds of bases so that the proper arrangement maybe secured for alargevariety of conditions. i i

V In the form of the invention shown in the drawing, the numeral 1designates the elongated'body portion of a pin which may be formed fromstockmaterial by swagingor forging to produce the elongated tapered bodyportion of the pin and a tapered lower end, indicated at 2 in thedrawing. Below the tapered portion 2 there is provided a cylindricalextension 3 of reduced size being threaded at its lower end forreceiving a nut 4 which engages. a washer 5 disposed be-v neath thecross-arm or supporting structure. The pin is provided with a basemember 6 having a conical-shaped socket which is cut away, as shown at 7to provide ribs 8 for The upper portion of the engaging the taperedportion 2 of the pin. This enables the socket member to grip the pin andhold it more firmly against rotation. It also makes it possible toeasilyit the individual pins and socketswhere necessary. It When the parts areassembled there is foundany irregularity a drift tool may be driven intothe tapered socket to bring the socket to proper taper, or, the socket.maybe easilyreamcd to true shape. I claim 1. The combination with aninsulator pin,

of abase for supporting-said pin, said base having a -socket forreceiving said pin, the wall of said socket being recessed to providecontact between said socket and pin for a portion only of the surface ofsaid pin while the portion of said pin disposed in said socket has acontinuously curved circular outer surface.

2. The combination with aninsulator pin, a

of aseparately formed base having a socket:

for receiving said pin, said soeket'having longitudinally extendingnarrow ribson the inner facethereo'f for engaging the surface of saidpin, said ribsbeing of less than degrees extent circumferentially. ofsaid socket. 3 y i i 3. The combinationwith an insulatorpin, of a basehaving a socket for receiving the lower end of said pin, said 'pin beingenlarged 'at the upper end of said socket to limit the movement of said"pin into said socket, and an extension on said pin below said socket forattaching said pin to a supporting structure, said socket having morethan two. longitudinally extending narrow ribs for engaging the surfaceof said pin.

,4. An insulator support comprisinga pin having an elongated bodymember, and a tapered portion at the lower end of said body member, anda separately formed base for said pin. said base having a tapered socketprovided with more than two longitudinally extending inwardly projectingnarrow ribs each of less than 90 degrees extent circumferentially forengaging the tapered portion of said pin; y I

5. Ali-insulator support comprising a pin having an elongated bodymember, a tapered portion at the lower end of said bodymember. andacylindrical extensionbelow said.

socket provided with more than two inwardsocket of said base member andfor clamply projecting longitudinally extending naring said pin and basemember on a supportrow ribs of less than 90 degrees extent cirinstructure. 10 cumferentiallynf said socket for engaging in testimonywhereof I have signed my 5 the tapered base portion of said in, and aname to this specification on this 26th day threaded member on saidcylindrical extenof Aug, A. D. 1925. sion for drawing said pin into thetapered ARTHUR O. AUSTIN.

